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DPTSV Example

To solve the equations

Ax = b,

where A is the symmetric positive definite tridiagonal matrix

A = $\displaystyle \left(\vphantom{ \begin{array}{rrrrr} 4.0 & -2.0 & 0 & 0 & 0 \\... ... 0 & 0 & 15.0 & 25.0 & 8.0 \\ 0 & 0 & 0 & 8.0 & 5.0 \end{array} }\right.$$\displaystyle \begin{array}{rrrrr} 4.0 & -2.0 & 0 & 0 & 0 \\ -2.0 & 10.0 & ... ....0 & 0 \\ 0 & 0 & 15.0 & 25.0 & 8.0 \\ 0 & 0 & 0 & 8.0 & 5.0 \end{array}$$\displaystyle \left.\vphantom{ \begin{array}{rrrrr} 4.0 & -2.0 & 0 & 0 & 0 \\... ... 0 & 0 & 15.0 & 25.0 & 8.0 \\ 0 & 0 & 0 & 8.0 & 5.0 \end{array} }\right)$  and  b = $\displaystyle \left(\vphantom{ \begin{array}{r} 6.0 \\ 9.0 \\ 2.0 \\ 14.0 \\ 7.0 \end{array} }\right.$$\displaystyle \begin{array}{r} 6.0 \\ 9.0 \\ 2.0 \\ 14.0 \\ 7.0 \end{array}$$\displaystyle \left.\vphantom{ \begin{array}{r} 6.0 \\ 9.0 \\ 2.0 \\ 14.0 \\ 7.0 \end{array} }\right)$.

Details of the LDLT factorization of A are also output.

Example program
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